Welcome, aokayre or Robert!

You've had so many diagnoses that I'm wondering if maybe you should consider a different route. Instead of asking what the name of your disorder is, maybe concentrate on finding ways to get rid of it or at least to cut down on your misery?

You've probably been doing that all along and have found some things that help--the best positions to sleep in, the best kind of chair to sit in, whether walking makes it worse or helps, and whether changes in your diet or some medicine you've been taking might make a difference.

I have similar problems with burning and pain, sometimes a sudden sharp pain, sometimes a persistent ache. I try not to go to doctors about any back-related pain because it seems as if most back problems aren't helped by the solutions doctors offer (surgery, for instance).

We all develop back problems as we get older. You don't mention your age but even a fairly young person can start having some problems of aging. I remind myself that my back problems are probably age catching up with me and that everyone starts to wear out sooner or later--but I do try to find ways to deal with the pain, burning, stiffness, etc. Swelling is a trickier problem to tackle and might need a doctor's attention.

It sounds as if you've ruled out Buerger's disease, perhaps because you don't smoke? If Buerger's disease might still be a possibility, it's pretty serious and definitely not something you should ignore:

Smoking and Buerger’s Disease | Overviews of Diseases/Conditions | Tips From Former Smokers | CDC

I hope you will find some useful answers soon. You've had to go to entirely too many doctors.